In(1) SeriesCoefficient[1/(1-x),{x,0,n}]
Out(1) (-1)^n*Binomial[-1,n]
Next,
In(2) FunctionExpand[(-1)^n*Binomial[-1,n],Assumptions->Element[n,Integers]]
OUt(2) ComplexInfinity
In(3) Table[(-1)^n*Binomial[-1,n], {n,-2,2}]
Out(3) {0,0,1,1,1}
Incidentally, FullSimplify in place of FunctionExpand yields the same
result, ComplexInfinity. I wonder if this misleading answer is a
result of FunctionExpand and FullSymplify resorting to the Gamma
Function for the simplification?
Is this a bug or a feature?
Thanks,
Jack